1. Field of the Invention
A beverage container lid is disclosed which includes a foldable tear strip flap that may be fastened in the open position or closed position permitting pouring and resealing, with minimal interference with drinking from the defined opening. More particularly, the present invention relates to a beverage container lid having a tear strip flap hinged so as to allow for easy opening, fastening in the open position, and closing and is readily formed in a reproducible manner to ensure tab locking in the open position.
2. Description of the Background Art
Beverage container lids that fasten over the lip of disposable containers are well known. These lids serve various functions including: the prevention of spilling the contents of the container; the prevention of heat loss or gain; and the addition of structural stability to prevent distortion of the container's shape. In their elementary form, these lids are comprised of a flat lid surface in the shape of the container's opening and a sealing channel or skirt running the rim of the lid surface to secure the lid to the container. This basic design has the drawback that in order to gain access to the contents, the entire lid must be removed. Given the particular use situation (e.g., walking, riding in a vehicle, etc.), complete removal of the lid is neither desirable nor easily accomplished.
Various advances have been made over the basic lid which incorporate an openable tear strip flap. See for example, U.S. Pat. Nos. 3,977,559; 4,090,660; and 4,210,272. These advances allow one limited access to the container while providing for closure of the major part of the container's opening. Since no means exists with these advances to secure the tear strip flap, the individual using these lids may find that the tear strip flap interferes with the convenient and unobstructed use of the opening, particularly drinking from the opeing when straws are not available.
Another advance in lid design is represented by U.S. Pat. No. 4,106,660. Access to the container is achieved by a total separation of the tear strip flap from the remainder of the lid. With the aid of a structural cavity in the tear strip flap, the flap may be replaced to seal the opening. However, when the flap is removed there is no built-in location to store the flap until it is required for closure of the container.
A further advance in container lids was made when a means was developed to secure the tear strip flap in the open position so as not to interfere with access to the container. See, U.S. Pat. Nos. 3,847,300; 3,994,411; 4,202,459; 4,322,015; 4,460,103; and 4,473,167. In all of these improvements, the tear strip flap remains attached to the lid by a simple one fold hinge line and is secured in the open position by any of several means: (1) a pair of external frictional clamps on the flap that, when the flap is folded into the open position, engage the distal rim ('300); (2) a pull tab on the tear strip flap that is inserted into a slit for a straw orifice ('411); (3) a slot in the body of the lid that resiliently holds the sealing skirt on the rim of the tear strip flap in the open position ('459); (4) a tear strip flap held open by wedging of the flap against one or more studs projecting above the surface of the lid ('015); (5) an elevated portion of the pull flap is inserted into a complementary depressed well section ('103); and (6) a tear strip flap that is wedged into a depression in the lid's surface designed so as to accept the flap and hold it in the open position by the force exerted between the sealing skirt of the flap and the distal wall of the depression ('167).
In normal use the above-described flaps are often too stiff to easily fasten open, too loose to stay in the fixed open position, too difficult to release and easily close, unable to be repeatedly opened and revealed difficult to fabricate accurately and often, too flimsy if fabricated with anything but heavy gauge materials.
As can be seen from the above discussion, a need exists for a beverage container lid that includes a means for limited access that is easy and reliable in its operations of opening, fastening in the open position, and closing.